Direct reading speed caliper



Aug. 13, 1935. H. B. LEHMAN ETAL DIRECT READING SPEED CALIPER Filed May 5, 1934 x 987 I1.9714173 37nm/22ww34465563 fixed barreliand by reference toa longitudinal VPatented Aug. 13, 19,35

Harry B. Lehman andManuel F. Arias, f

' Miami, Fla.

Application May 5, 1934,seria1N0. 724,185

" 4 claims. (o1. .fis- 166; rl'his `invention relates to measuring instruments and particularly to calipers.

The general object of this invention is to provide an instrument of thischaracter which is` .particularly adapted `forthe useof ordinary mechanics, unskilled in the use of micrometers and such instruments of extreme precision. Such instruments reading in thousands of an inch or inmillimeters must be translated by the orlOl .ydinary mechanic. into` terms he is familiar with and constantly uses. Such an ordinary mechanic is perfectly familiar withV and constantly uses fractions of an inch, as onefsixteenthjonethirty-i second, one sixty-fourth, etc., but he cannot 1 readily, if at all, translate thousandths of an inch into these terms and hence more particularly it is our object toprovidea caliper which, While capable of approximate' measurements of oneA thousandth of an inch, if necessary, is based upon the use of theordinary units of measurements as one-half, one-fourth' toner-eighth or: one sixtyhaving no, Yor very fourth-fof Vaninch. l l

A further object is `to provide'ian instrument of this character `which maybe very rapidly'and" easily read andused', particularly bymechanics little,` knowledge of the, use of micrometers.y f f A further object in'this connection is toprovide a caliper in which the units .of one-sixteenth oi an inch or the multiples thereof `are readby a vertical seriesof `graduations on the lxed barrel ,and` in which fractionsv of, said. units '(as one ing drawing, whereinz-fi; 1

thirty-second or five thirty-seconds, for instance, or vone, sixty-fourth or eleven sixty-'fourths,. for instance) are readl through an `aperture on `the series of graduations, on the spindle of the instru. ment and with referenceto` the graduations on the rotatable barrel, the numbers .on the spindle `giving the numerator of', theiraction,A the num-A bers on the rotatable barrel giving the denomi-` naturL74 1 `Other obiectswill appearin the` course of the following description. t i

Our invention is illustrated in ,Figure 11u is :an elevationY of a` caliper 1 constructed in .accordance with eur invention; 1 Figure 2 is a longitudinal sectionahview :theref,throughsV l ,Q Figure 3 is an .elevation .ofthe fixed barrel` showing the scale used thereon; l V1 Figurel is a projection o1 a portion of the rotatable barrel, showingthe graduationsthereon; Figure 5. is a projection or flattened out `viewthe accompany-'-` of a portion of vthe surface of the spindle showing the graduations thereon.

1 Referring tov the drawing, I0 designates the yoke orframeof the caliper having at one end the anvil i Iwhich is screw-threaded into the terminal end l2 of the frame so that it may be adjusted to take up wear and compensate for infaccuracies and which is Vadapted to be held in set position by means of a screw |3. The opposite end of the frame is formed with the collar i-l and disposed within this collarand held thereby against rotation is a -xed barrel 115. barrel projects below Ythe collar I4 andis` there reduced in diameter as at i6 and formedn with the sight aperture il, The barrel l5 extends upward above the upper end of the Y frame and disposed within this barrel is the internallyscrew-threaded element i8, the upper endof this element plQf jecting out 'slightly beyond the upper'endv of the barrel` and being split so that a nut IS may be engaged therewith whereby the elementl I8, may' be contracted from time however. Y This V)element as atZli, these threads to the inch. l

to time to take up Wear.

` Any other means `for thispurpose may be used,

I8 is internally threaded having a pitch of sixteen Coacting with the iixed barrel l5 is the rotatable barrel 2| which fits snugly over the xed barrel and which carries within it the spindle 22, `that portionV of the `spindle disposed within thel barrel 2| being threaded as at 23, these threads having the same pitch as. the threads 20. Thus, it will be se tation of the barrel 2i en that'a complete roi-.- upon the barrel l5 will move the barrel 2| and the spindle 22 a distance of one-sixteenth of an inch.

The barrel 2| is slightly beveled at its inner end and the upper end of the barrel is knurled as at 2li and preferably provided with a head 25 of relatively small diameter and also knurled. This head 25 is vfor the purpose of permitting quick rotation' of the barrel; means whereby, whenth ing Vthe anvil or appro 2l *and also to provide e spindle 22 is approach-- aching an object being measured, the force applied to the barrel and the spindle may be reduced by operating the barrel by means of the 'head 25 instead ofl by operating the `barrel directly l While we do not wish' Vto be limited to the details 'of construction, it will be seen .that the upper end of the spindle 22 is enlarged as at 26, that, this is sweated into the upperend of the barrel 2 tand 4that the head' 25 is formed as part .of the spindle. l

The fixedbarrel i|l5 fro m a point just above-the sii collar lli is provided with a longitudinally extending series of graduations designated 2i, the graduations indicating inches and fractions thereof, the graduations being one-sixteenth of an inch apart and starting with an index point designated naught and terminating with an index mark indicating two inches though, of course, we do not wish to be limited to the length of the barrel.

In view of the fact that the screw-threads 2G and 23 haveV a pitch of sixteen to the inch, it will be obvious that a complete rotation of the barrel 2l in either` direction will cause the barrel 2l with its spindle 22 to move one-sixteenth of an inch, which movement is indicated by the graduations 2'?.

The lower end of the barrel 2i, as shown in Figure l, is provided with graduations 29 extending circumferentially around the barrel There are four main graduations, one designated and diametrically opposite'this index or naught graduation is the graduation 32. Half way between the graduations 0 and 32 are graduations numbered "64. Obviously a complete rotation of the barrel to bring the naught graduation from a point over the vertical line 28 to a point again over the vertical line 28 on the barrel l5 will mean that the barrel 2l has been rotated through a complete revolution. Equally obviously, when the barrel has been rotated through a` half revolution, it will have moved through a space of a thirty-second of an inch and the numeral 32 will be above the line 2S. If the barrel has been moved a quarter turn, one or the other of the numerals 64 will come opposite the line '23 which Will indicate that the barrel and spindle have been longitudinally shifted one sixty-fourth of an inch. Intermediate the numerals 0, 32 and "64, the barrel is provided with a series of graduations which are sixteen in number between each two numerals. Thus these minor divisions of scale 29 are indicated as half of a sixty-fourth, a quarter of a sixty-fourth, an eighth of a sixtyourth and a sixteenth of a sixty-fourth.

rIhe spindle 22, as shown in Figure 5, is provided with a plurality of longitudinal series of numerals capable of being read through the apenture i, the numerals of three of the series being 1% of an inch apart and of the other beneath the Zero index being 1/8 of an inch apart. These several series ci numerals are disposed at intervals of ninety degrees apart so that these several series of numerals come immediately beneath and in vertical alinement with the graduation numerals on the lower end of the sleeve 2l.

In register with the index mark 0 on the barrel, the spindle carries a vertical series of numerals reading from one to fifteen and then again from one to fifteen and increasing by increments of two. Registering with the 32 mark on the barrel are a longitudinal series or" numerals read-Y ing from one to thirty-one and then from one vto thirty-one and increasing by increments of two.

v Registering with the mark "64 to the right hand of the zero mark on the lower end of the barrel, are a series of numerals reading from three downward to sixty-three and then from three downward to sixty-three and increasing by increments of four. Registering with the mark 64 on the left hand of the zero mark on the rotatable barrel are series of numerals starting with 1 and proceeding to 6l and then from l to 6l progressing by increments of four as l, 5, 9, etc. Thespaces between the numerals 0 to 32 and 64 on the barrel are subdivided into sixteenths so that the rotation through one of these subdivisions will give a longitudinal movement of onehalf of a sixty-fourth, a fourth of a sixty-fourth, an eighth and a sixteenth of a sixty-fourth, carrying the scale down in terms as the mechanic knows it. It will be seen that this caliper may be easily read by any mechanic in terms of those fractions of an inch with which he is entirely acquainted, as one-half, one-fourth, one-eighth, one thirty-second, and one sixty-fourth and that in use, he will read the sixteenth units on the scale 2 or he may read even graduations of scale 2 o-n this scale and his odd graduations through the aperture il. The measurements of and less than one-sixteenth he will read through the aperture il and on scale 2S, reading the numerator of thel fraction through the aperture il and the denominator on scale 29 as /32 or 7/64 or 17/64, etc. If he Wishes a dimension less or greater than the fraction indicated, he can turn the barrel a space indicated by a minor subdivision of scale 29.

It will be seen that all or" the subdivisions of the scales used are based upon commonly used and VeasilyA understood fractions of an inch; thus the scale 2 is divided into sixteen subdivisions to an inch, the screw, of course, having sixteen threads to an inch, the scale 29 is subdivided into one-half and again into one-quarter of ra 16th which equals l/32 or l/Ge of an inch and the scale 22 reads from l to 63 so as to measure from l/Gli of an inch to (i3/Gli of an inch while the scale 29 between 0 and 64 and between-"64 and 32 is still further subdivided into sixteenths so that there are sixty-four minor sub-divisions around the entire scale 29. It is impossible to subdivide this scale 29 in any other way and permit the mechanic to readily read halves, quarters or eighths and sixteenths of 1/ 64.

We claim:-

1. A direct reading speed caliper including a frame, a fixed inner barrel and an anvil carried by the frame; a rotatable, longitudinally movable outer barrel and a spindle carried thereby, the rotatable barrel extending over the fixed barrel and the spindle extending through the fixed barrel; the xed barrel and the spindle having interengaging screw-threads having a pitch of sixteen threads tothe inch; the iixed barrel having a longitudinally extending index line and a longitudinally extending scale thereon reading in sixteenths of an inch; the rotatable barrel having a circumferential scale coordinated with the vertical index line and having a zero index point; a numeral indicating 1/32 of an inch diametrically opposite the zero point and two numerals indicating l/64 of an inch disposed 90 from and on each side of the Zero point; the spindle having four longitudinal series of numerals three of these series being spaced apart 1/ 16 of an inch and the fourth being spaced apart 1/3 of an inch and in alinement with the four subdivisions of the scale on the rotatable barrel and respectively coacting therewith to indicate fractions of an inch, the numerals on the spindle which are spaced apart le of an inch and the numerals on the rotatable barrel alined therewith indicating respectively the numerators of said fractions and the denominators thereof.

2. A caliper including a frame, a xed barrel and an anvil carried by the frame; a' rotatable and longitudinally movable barrel and a spindle carried thereby, the'rotatable barrel extending over the xed barrel, and the spindle extending therethrough; the xed barrel andthe spindle having engaging screw-threads having a pitch of y sixteen to the inch; the fixed barrel having a l longitudinally extending index line and a longitudinally extending scale thereon reading in sixteenths of an inch; the rotatable barrel having a `circumferential scale co-ordinatedV with the vertical index line and having a zero point, a numeral indicating 315 of an inch diametrically opposite the zero point and two numerals indicating 1/64 of an inch disposed 90 from and on p each side of the zero point, a spindle having four longitudinal series of numerals in alinement with the four subdivisions of the scale on the rotatable barrel, the numerals of three of these series being spaced apart of an inch and the remaining series having its numerals 1A; of an inch apart,

l said four series of numerals respectively coacting with the scale on the rotatable barrel to indicate fractions,` the numerals on the spindle which are spaced apart 1*-6 .of an inch and the numerals on the rotatable barrel alined therewith indicating respectively the numerators and the denomiunators of said fractions; `the extremity of the barrel adjacent the anvil being formed with an aperture through which the numerals on the spindle can be successively seen as the rotatable barrel and spindle are rotated.

3. A caliper including a frame, a fixed barrel, an anvil carried by the frame, a rotatable, longitudinally movable barrel surrounding the fixed barrel, and a spindle carried by the rotatable barrel and extending throughV the center of the xed barrel toward the anvil, the fixed barrel having interior screw-threads and the spindle having coacting screw-threads, the screw-threads having a certain definite unit of pitch, the fixed barrel having a longitudinally extending index line and longitudinally extending scale thereon reading in the same units as the unit of pitch of `said screw, the rotatable barrel having a circumferential scale coordinated with the vertical index lines and having a zero index point, and numerals spaced equi-distantly around the barrel and indicating fractionsof` said unit, the spindle having a plurality of longitudinal series of numerals, the series being equal in number to the number of numerals on the rotatable barrel and thenumerals of each series being spaced from each other a distance equal to the unit of measurement used for the screw-threads, the series of 3 numerals reading downward toward the free end of the spindle, the several series of numerals coacting with the several subdivisions and their numerals on the rotatable barrel to indicate fractions or multiples of the unit measurement, the numerals on the spindle which are spaced apart -fg of an inch indicating the numerators of said fractions and the numerals on the barrel alined therewith indicating the denominators of the fractions.

4. A caliper including a frame, a iixed barrel andan anvil carried by the frame; a rotatable and longitudinally movable barrel and a spindle carried thereby, the rotatable barrel extending over the xed barrel and the spindle extending therethrough; the xed barrel andthe spindle and barrel'having engaging screw-threads having a pitch of sixteen to the inch; the xed barrel having a longitudinally extending index line and a longitudinally extending scale thereon'reading in sixteentlis of an inch; the rotatable barrel having a circumferential scale cfa-ordinated with the vertical index line and having a zeropoint, a numeral indicating se of an inch diametrically opposite the zero point and two numerals indieating 1/64 of an inch disposed 90 from and on each side of the zero point, the spaces between the four divisions above indicatedbeing in turn divided to give one-half of a sixty-fourth, one fourth of a sixty-fourth, one-eighth of a sixtyfourth and one-sixteenth of a sixty-fourth,` the spindle having four longitudinal series of numerals in alinement Vwith the four main subdivisions of the scale on the rotatable barrel, the

numerals oi three series being spaced apart le of an finch and the fourth'series being 1/8 of an inch apart, said four series of numerals respectively coacting with the scale on the rotatable barrel to indicate fractions, the numerals on the HARRY B. LEHMAN. MANUEL F. ARIAS. 

